Practice Test 12

A proton and an electron are separated by $r = 1.0 \times 10^{-10},\text{m}$. Using the same constants and particle properties ($m_p = 1.67 \times 10^{-27},\text{kg}$, $m_e = 9.11 \times 10^{-31},\text{kg}$, $q = 1.6 \times 10^{-19},\text{C}$, $G = 6.67 \times 10^{-11}$, $k = 9.0 \times 10^{9}$), which pair of magnitudes is closest to the correct values for $F_{\text{grav}}$ and $F_{\text{elec}}$?

A proton and an electron are separated by a distance of $r = 5.3 \times 10^{-11},\text{m}$ (about the Bohr radius). Use $m_p = 1.67 \times 10^{-27},\text{kg}$, $m_e = 9.11 \times 10^{-31},\text{kg}$, $q_p = +1.6 \times 10^{-19},\text{C}$, $q_e = -1.6 \times 10^{-19},\text{C}$, $G = 6.67 \times 10^{-11},\text{N·m}^2/\text{kg}^2$, and $k = 9.0 \times 10^{9},\text{N·m}^2/\text{C}^2$. What is the ratio $F_{\text{elec}}/F_{\text{grav}}$ between them?